Pretty obvious what’s happening, scitwi sirenified and studying magical creatures and biology. This is based on a common on my other piece about the trope, ‘Attractive Bent Species’ and it lead me to the squirrel scene in Arthur and the Sword in the Stone animated movie of yor. Well… reverse genders in this situation and you have a human turned into a creature and unwittingly having one of them attracted to her. Her being human and all well I think you can piece the rest together and she’s not comfortable with this.